The goal of this proposal is to secure funding to purchase a high sensitivity positron emission tomography (PET) scanner for neuroimaging studies in non-human primates. The specific system we propose is the ?PET scanner manufactured by Brain Biosciences Inc. The system has 2 mm reconstructed spatial resolution, 13- mm-thick high-density scintillators for high sensitivity, and a field of view sufficient to encompass the entire rhesus monkey brain. This will replace an obsolete PET scanner (microPET P4, installed 2001) which is no longer supported by the manufacturer and for which certain key components are no longer available. The lack of support for this existing scanner is a huge vulnerability for a wide range of neuroimaging research that is ongoing in nonhuman primates at our institution. The ?PET system will be installed in the Multimodal Imaging Core at the California National Primate Research Center (CNPRC) at UC Davis, one of seven national primate centers supported by the NIH. The system will thus be available to all researchers who utilize nonhuman primate models at the CNPRC, including many UC Davis faculty as well as collaborators across the nation. The system will be operated and maintained by staff from the Center for Molecular and Genomic Imaging, a core facility at UC Davis that provides the infrastructure and expertise to conduct in vivo imaging studies in animal models. CMGI also has its own cyclotron and radiochemistry facilities and routinely supplies a wide range of tracers and radioligands to the CNPRC for PET studies. The system will be used to support ongoing and future planned neuroimaging studies related to aging, neuropsychiatric disorders, developmental disorders, pharmacokinetic evaluation of new diagnostic and therapeutic agents, effects of environmental exposures and many other areas of biomedical research where the nonhuman primate brain serves as an informative and relevant model for ultimate human translation.